Barack Obama has warned that public anger over bankers' pay could prevent him from providing further help to the troubled financial industry.

Speaking ahead of the G20 summit in London this week, the US president gave a clear signal that he will not tolerate excessive bonuses and 'rewards for failure', at a time when his administration is propping up the sector.

"At a time when everybody is needing to sacrifice, there has to be a similar sense of sacrifice on the part of those that helped to precipitate this crisis," Obama told the Financial Times.

Goodwin's £709,000 annual pension has become one of the symbols of the crisis, and shareholders in Royal Bank of Scotland are expected to vote against the payoff later this week.

Faced with such clear signs of public disdain, Obama argued it was vital that the banks show restraint at time when his administration is pushing through a $1tn bailout package.

"If voters perceive it is a one-way street, that we are just pouring more and more money into institutions and seeing no return other than avoiding catastrophe, then it is harder to make an argument for further intervention," he said.

Obama also said it was vital that world leaders at the G20 meeting delivered "a strong message of unity in the face of crisis".

But it is far from clear that Gordon Brown will succeed in delivering a "global new deal" to drag the world away from a long, damaging downturn. A draft version of the final communique, leaked over the weekend, appeared to show that the UK was pushing for a $2tn package - but German chancellor, Angela Merkel, has already downplayed expectations of a major deal at the summit.